CN103023532B - Device and method for testing influences of direct-current transmission line harmonic on noise of communication line - Google Patents
Device and method for testing influences of direct-current transmission line harmonic on noise of communication line Download PDFInfo
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- CN103023532B CN103023532B CN201210563165.0A CN201210563165A CN103023532B CN 103023532 B CN103023532 B CN 103023532B CN 201210563165 A CN201210563165 A CN 201210563165A CN 103023532 B CN103023532 B CN 103023532B
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Abstract
The invention relates to a designed device for testing influences of direct-current transmission line harmonic on noise of a communication line. The device comprises an anechoic chamber, a twin-twisted telephone line, a copper wire, a harmonic generator, a resistor R1, a telephone, an exchanger, two non-inductive resistors and two psophometers, the twin-twisted telephone line, the copper wire, the harmonic generator, the resistor R1, the telephone and the exchanger are arranged inside the anechoic chamber, two ends of the copper wire are both connected with the harmonic generator, the resistor R1 is serially connected on the copper wire, one end of the twin-twisted telephone line is connected with the telephone while the other end thereof is connected with the exchanger, the exchanger is further connected with a remote telephone arranged outside the anechoic chamber, the two non-inductive resistors are used for replacing the telephone and the remote telephone during test, and the two psophometers are used for testing equivalent noise electromotive force of the two non-inductive resistors respectively. By the device, the influences of the direct-current transmission line harmonic on the noise of the communication line can be tested indoors, and accordingly testing experiment cost is lowered, and precision of research results is improved.
Description
Technical field
The present invention relates to high voltage power transmission and transforming engineering electromagnetic compatibility technology field, refer to that particularly a kind of DC power transmission line harmonic wave affects testing apparatus and method to communication line noise.
Technical background
DC power transmission line can produce harmonic voltage and the harmonic current in a large amount of audioranges when normal operation, by perception and Resistive Coupling, produces noise nearby in voice frequency telephone loop, reduces speech quality.Since the seventies, generally adopted " equivalent disturbing current " value as the standard of restriction direct current harmonics level, because people's ear is the most responsive to the sound between 12 ~ 24 characteristic harmonics frequencies, state's reference frequency is got 800Hz still.The formulation of equivalent disturbing current limitation standard is subject to the impact of following factor: noise electromotive force limits value in the line loop being caused by DC power transmission line that 1) Office of the Telecommunications Authority allows; 2) situation that approaches of DC power transmission line and line loop; 3) affected line loop quantity and type; 4) the line loop soil resistivity along the line being disturbed.Meanwhile, equivalent disturbing current numerical limits is crossed and sternly can be caused DC filter cost too high.
What at high voltage dc transmission technology, develop is early stage, the problem that direct current system forms potential interference to communication system shows more seriously, this is because 70-80 age world wide comprises that China is also widely used the backbone network transmission of audio telephone signal that long-distance aerial line forms, disturb to external world very responsively, the direct current harmonics level limit value of therefore formulating in this period is stricter.But occurred to develop by leaps and bounds since later stage eighties telecommunication technology, the New Generation of Communication network that is representative by optical fiber communication and digital communication is large with its capacity, the advantages such as antijamming capability is strong are popularized rapidly, with the development of China, attract attention in the world the most especially, in the later stage nineties, basically formed and take optical fiber as backbone network, take digital communication as main communication network, older generation's communication lines such as aerial line have been eliminated, therefore the impact of re-examine DC transmission system on communication system now, research formulate in early days and the direct current harmonics level limit value that continues into the present whether to be applicable to the present situation be very necessary.This study general carries out at outdoor scene at present, and research cost is higher, affected by scene temperature, humidity etc., and the precision of outdoor research is also difficult to be guaranteed.
Summary of the invention
Object of the present invention will provide a kind of DC power transmission line harmonic wave to affect testing apparatus and method to communication line noise exactly, the DC power transmission line harmonic wave that these apparatus and method could be carried out actual field concentrates on laboratory to the research work of communication line noise impact and completes, reduce research cost, improved the precision of result of study.
For realizing this object, the designed DC power transmission line harmonic wave of the present invention affects testing apparatus to communication line noise, it is characterized in that: it comprises anechoic chamber, be arranged in the twisted pair telephone line in anechoic chamber, copper conductor, harmonic oscillator, resistance R 1, telephone set and interchanger, wherein, the two ends of described copper conductor are all connected with harmonic oscillator, described resistance R 1 is connected on copper conductor, one end of described twisted pair telephone line connects telephone set, the other end connection exchanger of twisted pair telephone line, described interchanger is also connected with the remote phone machine being arranged on outside anechoic chamber, it also comprises for replace two noninductive resistances of telephone set and remote phone machine when testing, and for testing respectively two psophometers of two noninductive resistance equivalence noise electromotive force.
In described copper conductor one section parallel with in twisted pair telephone line one section.
The parallel-segment length of described copper conductor and twisted pair telephone line is 8 ~ 12m.
Spacing between described copper conductor and the parallel-segment of twisted pair telephone line is 20 ~ 50cm.
The resistance of described resistance R 1 is 1 ohm, and power is 50W, and the resistance of described noninductive resistance is 600 ohm.
Utilize above-mentioned DC power transmission line harmonic wave communication line noise to be affected to a method of testing for testing apparatus, it comprises the steps:
Step 1) operation telephone set is put through remote phone machine and is formed a talking path;
Step 2) telephone set and remote phone machine are replaced with a noninductive resistance respectively under the situation that keeps call;
Step 3) produces a harmonic current on copper conductor loop by harmonic oscillator, described resistance R 1 is for limiting harmonic current;
One section of twisted pair telephone line parallel with copper conductor described in step 4) is responded to the noise electromotive force producing on copper conductor;
Step 5) is used the equivalent noise electromotive force on two noninductive resistances of psophometer test, then with telephone set and remote phone machine, replaces above-mentioned two noninductive resistances, and tests the now communication effect of telephone set and remote phone machine;
Step 6) replaces telephone set and remote phone machine with two noninductive resistances again, control harmonic oscillator and produce another harmonic current, and test by psophometer the equivalent noise electromotive force that different harmonic currents disturb lower two noninductive resistances to produce, finally with telephone set and remote phone machine, replace above-mentioned two noninductive resistances, and test the communication effect that telephone set and remote phone machine are descended in now different harmonic currents interference, completed the test of DC power transmission line harmonic wave on the impact of communication line noise.
After described step 6), also comprise step 7): by two lines of twisted pair telephone line separately, two line parallels are separately arranged, distance between two lines is separately 0.4 ~ 0.6m, with two noninductive resistances, replace telephone set and remote phone machine, by psophometer, testing now two equivalent noise electromotive force that noninductive resistance produces, with telephone set and remote phone machine, replace two noninductive resistances again, and test twisted pair telephone line two lines now separately after the communication effect of telephone set and remote phone machine.
Described step 2), step 6) and step 7) in substitution technique be: first telephone set and remote phone machine are connected in parallel on telephone set and remote phone machine with a noninductive resistance respectively under the situation that keeps call, then pull up telephone set and remote phone machine; Described step 5), step 6) and step 7) in replacement method be: first telephone set and remote phone machine are connected in parallel on respectively to two noninductive resistance two ends, then take off noninductive resistance.
Described harmonic oscillator produces the harmonic wave of 0 ~ 5KHZ, and this harmonic oscillator is the maximum harmonic current that can produce the 800HZ of 10A on copper conductor loop.
The present invention by arranging twisted pair telephone line, copper conductor, harmonic oscillator, resistance R 1, telephone set, interchanger, noninductive resistance and psophometer in anechoic chamber, realized indoor and carried out the test of DC power transmission line harmonic wave on communication line noise impact, reduce the cost of test experiments, improved the precision of result of study.In addition, these apparatus and method can be used to verify the applicability of mutual impedance computational methods between two-conductor; The shield effectiveness of shielding conductor is installed in checking additional; Investigate the coefficient of sensitivity of line loop under the present art; Investigate the horizontal servant's of different phone noise electromotive force subjective feeling.
Accompanying drawing explanation
Fig. 1 is structured flowchart of the present invention;
Fig. 2 increases the structured flowchart after line loop coefficient of sensitivity in the present invention.
Wherein, 1-anechoic chamber, 2-twisted pair telephone line, 3-copper conductor, 4-harmonic oscillator, 5-telephone set, 6-interchanger, 7-remote phone machine, 8-noninductive resistance, 9-psophometer.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail:
DC power transmission line harmonic wave in figure shown in 1 affects testing apparatus to communication line noise, it comprises anechoic chamber 1, be arranged in the twisted pair telephone line 2 in anechoic chamber 1, copper conductor 3, harmonic oscillator 4, resistance R 1, telephone set 5 and interchanger 6, wherein, the two ends of copper conductor 3 are all connected with harmonic oscillator 4, described resistance R 1 is connected on copper conductor 3, one end of twisted pair telephone line 2 connects telephone set 5, the other end connection exchanger 6 of twisted pair telephone line 2, interchanger 6 is also connected with the remote phone machine 7 being arranged on outside anechoic chamber 1, it also comprises for replace two noninductive resistances 8 of telephone set 5 and remote phone machine 7 when testing, and for testing respectively two psophometers 9 of two equivalent noise electromotive force of noninductive resistance 8.
In technique scheme, anechoic chamber 1 has good screening effectiveness, can get rid of external electromagnetic wave interference completely, and effectively prevents electromagnetic reflection by install absorbing material additional at wall, thereby simulation is in the Electromagnetic Wave Propagation process of open area.
In technique scheme, in copper conductor 3 one section parallel with in twisted pair telephone line 2 one section.
In technique scheme, the parallel-segment length of copper conductor 3 and twisted pair telephone line 2 is 8 ~ 12m.
In technique scheme, the spacing between described copper conductor 3 and the parallel-segment of twisted pair telephone line 2 is 20 ~ 50cm.
In technique scheme, the resistance of resistance R 1 is 1 ohm, and power is 50W, and the resistance of noninductive resistance 8 is 600 ohm.
Utilize above-mentioned DC power transmission line harmonic wave communication line noise to be affected to a method of testing for testing apparatus, it comprises the steps:
Step 1) operation telephone set 5 is put through remote phone machine 7 and is formed a talking path;
Step 2) telephone set 5 and remote phone machine 7 are replaced with a noninductive resistance 8 respectively under the situation that keeps call;
Step 3) produces a harmonic current on copper conductor 3 loops by harmonic oscillator 4, resistance R 1 is for limiting harmonic current;
One section of twisted pair telephone line 2 parallel with copper conductor 3 described in step 4) is responded to the noise electromotive force producing on copper conductors 3;
Step 5) is used the equivalent noise electromotive force on two noninductive resistances 8 of psophometer 9 tests, then with telephone set 5 and remote phone machine 7, replaces above-mentioned two noninductive resistances 8, and tests the now communication effect of telephone set 5 and remote phone machine 7;
Step 6) replaces telephone set 5 and remote phone machine 7 with two noninductive resistances 8 again, control harmonic oscillator 4 and produce another harmonic current, and the equivalent noise electromotive force that disturbs lower two noninductive resistances 8 to produce by the different harmonic currents of psophometer 9 test, finally with telephone set 5 and remote phone machine 7, replace above-mentioned two noninductive resistances 8, and test the communication effect that telephone set 5 and remote phone machine 7 are descended in now different harmonic currents interference, completed the test of DC power transmission line harmonic wave on the impact of communication line noise.
In technique scheme, due to the on-the-spot analog line limited length of setting up of experiment, in the situation that actual line loop susceptibility is very high, cannot on line loop, induce the sensitive noise electromotive force of people's ear, now can adopt following steps to increase line loop coefficient of sensitivity.After described step 6), also comprise step 7): by two lines of twisted pair telephone line 2 separately, two line parallels are separately arranged, distance between two lines is separately 0.4 ~ 0.6m, with two noninductive resistances 8, replace telephone set 5 and remote phone machine 7, by psophometer 9, testing now two equivalent noise electromotive force that noninductive resistance 8 produces, with telephone set 5 and remote phone machine 7, replace two noninductive resistances 8 again, and test 2 liang of lines of twisted pair telephone line now separately after the communication effect of telephone set 5 and remote phone machine 7, as shown in Figure 2.By above-mentioned steps, when using relatively little 800Hz electric current, just can induce larger noise electromotive force in telephony side, better simulate the impact of DC power transmission line harmonic wave on communication line noise under different occasions.
Described step 2), step 6) and step 7) in substitution technique be: first telephone set and remote phone machine are connected in parallel on telephone set and remote phone machine with a noninductive resistance respectively under the situation that keeps call, then pull up telephone set and remote phone machine; Described step 5), step 6) and step 7) in replacement method be: first telephone set and remote phone machine are connected in parallel on respectively to two noninductive resistance two ends, then take off noninductive resistance.
In technique scheme, harmonic oscillator 4 produces the harmonic wave of 0 ~ 5KHZ, and the capacity of harmonic oscillator 4 is 5 kilowatts, and this harmonic oscillator 4 is the maximum harmonic current that can produce the 800HZ of 10A on copper conductor 3 loops.
Communication effect method of testing in technique scheme is to select several measured to use disturbed phone and distant place phone to converse, and carries out subjective communication effect statistics, the call under each noise electromotive force is recorded simultaneously.
The content that this specification is not described in detail belongs to the known prior art of professional and technical personnel in the field.
Claims (6)
1. one kind is utilized DC power transmission line harmonic wave communication line noise to be affected to the method for testing of testing apparatus, described DC power transmission line harmonic wave affects testing apparatus to communication line noise, comprise anechoic chamber (1), be arranged in the twisted pair telephone line (2) in anechoic chamber (1), copper conductor (3), harmonic oscillator (4), resistance R 1, telephone set (5) and interchanger (6), wherein, the two ends of described copper conductor (3) are all connected with harmonic oscillator (4), described resistance R 1 is connected on copper conductor (3), one end of described twisted pair telephone line (2) connects telephone set (5), the other end connection exchanger (6) of twisted pair telephone line (2), described interchanger (6) is also connected with the outer remote phone machine (7) of anechoic chamber (1) that is arranged on, it also comprises for replace two noninductive resistances (8) of telephone set (5) and remote phone machine (7) when testing, and for testing respectively two psophometers (9) of the equivalent noise electromotive force of two noninductive resistances (8), in described copper conductor (3) one section parallel with in twisted pair telephone line (2) one section, it is characterized in that, the method of testing that DC power transmission line harmonic wave affects testing apparatus to communication line noise comprises the steps:
Step 1) operation telephone set (5) is put through remote phone machine (7) and is formed a talking path;
Step 2) under the situation that keeps call, use respectively a noninductive resistance (8) to replace telephone set (5) and remote phone machine (7);
Step 3) by harmonic oscillator (4), on copper conductor (3) loop, produce a harmonic current, described resistance R 1 is for limiting harmonic current;
Step 4) the upper noise electromotive force producing of described parallel with copper conductor (3) one section of twisted pair telephone line (2) induction copper conductor (3);
Step 5) use the equivalent noise electromotive force on psophometer (9) two noninductive resistances of test (8), then use telephone set (5) and remote phone machine (7) to replace above-mentioned two noninductive resistances (8), and test the now communication effect of telephone set (5) and remote phone machine (7);
Step 6) use again two noninductive resistances (8) to replace telephone set (5) and remote phone machine (7), control harmonic oscillator (4) and produce another harmonic current, and test by psophometer (9) the equivalent noise electromotive force that different harmonic currents disturb lower two noninductive resistances (8) to produce, finally use telephone set (5) and remote phone machine (7) to replace above-mentioned two noninductive resistances (8), and the communication effect of telephone set (5) and remote phone machine (7) is descended in now different harmonic currents interference of test;
Step 7): by two lines of twisted pair telephone line (2) separately, two line parallels are separately arranged, distance between two lines is separately 0.4～0.6m, with two noninductive resistances (8), replace telephone set (5) and remote phone machine (7), again by psophometer (9) the test equivalent noise electromotive force that now two noninductive resistances (8) produce, use again telephone set (5) and remote phone machine (7) to replace two noninductive resistances (8), and test twisted pair telephone line (2) two lines now separately after the communication effect of telephone set (5) and remote phone machine (7).
2. method of testing according to claim 1, is characterized in that: the parallel-segment length of described copper conductor (3) and twisted pair telephone line (2) is 8～12m.
3. method of testing according to claim 1 and 2, is characterized in that: the spacing between described copper conductor (3) and the parallel-segment of twisted pair telephone line (2) is 20～50cm.
4. method of testing according to claim 1, is characterized in that: the resistance of described resistance R 1 is 1 ohm, and power is 50W, and the resistance of described noninductive resistance (8) is 600 ohm.
5. method of testing according to claim 1, it is characterized in that: described step 2), step 6) and step 7) in substitution technique be: first telephone set and remote phone machine are connected in parallel on telephone set and remote phone machine with a noninductive resistance respectively under the situation that keeps call, then pull up telephone set and remote phone machine; Described step 5), step 6) and step 7) in replacement method be: first telephone set and remote phone machine are connected in parallel on respectively to two noninductive resistance two ends, then take off noninductive resistance.
6. method of testing according to claim 1, is characterized in that: described harmonic oscillator (4) produces the harmonic wave of 0～5KHZ, and this harmonic oscillator (4) is the maximum harmonic current that can produce the 800HZ of 10A on copper conductor (3) loop.
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| DE10019552A1 (en) * | 2000-04-20 | 2001-10-25 | Deutsche Telekom Ag | Measuring quality of digital or analog signal transmission by network, compares stored reference values with results from non-intrusive, in-service testing |
| CN101414851A (en) * | 2008-07-02 | 2009-04-22 | 北京网联直流工程技术有限公司 | Novel method for evaluating communication interference limit of extra-high voltage DC transmission system DC harmonic |
| CN101969349B (en) * | 2009-07-28 | 2014-08-13 | 中兴通讯股份有限公司 | Measuring method for space transmission power of receiving terminal under test in multi-access terminal |
| CN101969653B (en) * | 2009-07-28 | 2014-03-12 | 中兴通讯股份有限公司南京分公司 | Method for measuring receiving sensitivity of receiving terminal to be measured in multi-access terminal |
| CN202978929U (en) * | 2012-12-21 | 2013-06-05 | 中国电力科学研究院 | Device for testing noise impact imposed on communication lines by DC transmission line harmonic waves |
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